Union County, Illinois Natural Disaster Risk
FEMA National Risk Index assessment · IL
LowComposite Risk Score
National percentile: 55th
Union County faces low composite natural disaster risk (NRI Risk Index score 55.4, 55th national percentile), driven primarily by earthquake and strong wind exposure. Expected annual loss across all 18 hazard types is $15M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Union County carries a low composite natural disaster risk, with a National Risk Index score of 55.4 out of 100 — placing it in the 55th national percentile and below the national average for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $4M in expected annual loss and about 0.01 events per year; strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at High risk — $1M in expected annual loss and about 4.11 events per year; and heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at Medium risk — $2M in expected annual loss and about 10.63 events per year. Across all hazards, FEMA estimates $15M in expected annual loss for a population of 17K.
Beyond physical exposure, Union County has a high social vulnerability rating (how susceptible the population is to harm) and a medium community resilience rating (its capacity to prepare for and recover from disasters). That combination — a more vulnerable population with limited resilience — can amplify the human cost of any given event.
History supports the rating: Union County has received 15 federal disaster declarations since 1969, including 5 for flood events and 5 for severe storm events. The most recent was Covid-19 Pandemic (biological), declared in March 2020.
Among 102 Illinois counties, Union County ranks #50 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Earthquake | Medium | 0.01 / yr | $4M |
| Strong Wind | High | 4.11 / yr | $1M |
| Heat Wave | Medium | 10.63 / yr | $2M |
| Cold Wave | Medium | 1.11 / yr | $2M |
| Winter Weather | Medium | 7.74 / yr | $94K |
| Ice Storm | Medium | 0.89 / yr | $125K |
| Tornado | Low | 0.36 / yr | $2M |
| Drought | Low | 3.87 / yr | $240K |
| Landslide | Very Low | 1.53 / yr | $1K |
| Riverine Flood | Low | 2.32 / yr | $4M |
| Hail | Low | 3.38 / yr | $135K |
| Lightning | Low | 55.47 / yr | $120K |
| Hurricane | Very Low | 0.02 / yr | $18K |
| Wildfire | Very Low | 0.00 / yr | $2K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Union County has received 15 federal disaster declarations since 1969, most recently Covid-19 Pandemic in March 2020. Most frequent causes: Flood (5), Severe Storm (5), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2019 | Flood | Severe Storms and Flooding |
| June 2011 | Severe Storm | Severe Storms and Flooding |
| July 2009 | Severe Storm | Severe Storms, Flooding, and Tornadoes |
| March 2009 | Severe Storm | Severe Winter Storm |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| February 2005 | Snowstorm | Record/Near Record Snow |
| May 2003 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| May 2002 | Tornado | Severe Storms, Tornadoes and Flooding |
Showing the 10 most recent of 15 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Union County?
Union County has a composite FEMA National Risk Index score of 55.4 out of 100, placing it in the Low category and the 55th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Union County?
The three highest-rated hazards are Earthquake (Medium, $4M EAL), Strong Wind (High, $1M EAL), Heat Wave (Medium, $2M EAL). These account for most of the county's expected annual losses.
How does Union County compare to other Illinois counties?
Union County ranks #50 of 102 Illinois counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Union County had?
FEMA records 15 federal disaster declarations for Union County since 1969, most often 5 for flood events and 5 for severe storm events. The most recent was Covid-19 Pandemic, declared in March 2020.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Union County's $15M EAL is a statistical average, not a guarantee for any specific year or address.